Erreur lors de la création du file Excel

J'utilise vb.net pour créer un file excel, mais cela me donne l'erreur de ne pouvoir ouvrir le file car le format de file ou le file d'extension de file n'est pas valide.

Dim excelLocation As Ssortingng = txtLocate.Text + txtFilename.Text.Trim + ".xlsx" Dim source1 As New BindingSource Dim APP As New Excel.Application Dim worksheet As Excel.Worksheet Dim workbook As Excel.Workbook If System.IO.File.Exists(excelLocation) = False Then System.IO.File.Create(excelLocation).Dispose() End If workbook = APP.Workbooks.Open(excelLocation) worksheet = workbook.Worksheets("sheet1") Dim columnsCount As Integer = dgvList.Columns.Count For Each column In dgvList.Columns worksheet.Cells(1, column.Index + 1).Value = column.Name Next For i As Integer = 0 To dgvList.Rows.Count - 1 Dim columnIndex As Integer = 0 Do Until columnIndex = columnsCount worksheet.Cells(i + 2, columnIndex + 1).Value = dgvList.Item(columnIndex, i).Value.ToSsortingng columnIndex += 1 Loop Next workbook.SaveAs() workbook.Close() MsgBox("Save!")